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Serial I/O Architecture Ordered-Set/Sequence Reception And Protocol For Managing Sequences

IP.com Disclosure Number: IPCOM000124010D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-05

Publishing Venue

IBM

Related People

Elliott, JC: AUTHOR [+6]

Abstract

Disclosed is the architecture that describes the procedures for ordered-set reception and sequence reception. The architected procedures provide a method of receiving and recognizing unique groups as ordered sets, and receiving and recognizing consecutive strings of unique groups as sequences, respectively. Disclosed is the architecture that describes the protocol for managing sequences, which includes a method to keep both ends of a link in step when frame transmission is not being performed, called "control synchronization".

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This is the abbreviated version, containing approximately 13% of the total text.

Serial I/O Architecture Ordered-Set/Sequence Reception And Protocol
For Managing Sequences

      Disclosed is the architecture that describes the
procedures for ordered-set reception and sequence reception.  The
architected procedures provide a method of receiving and recognizing
unique groups as ordered sets, and receiving and recognizing
consecutive strings of unique groups as sequences, respectively.
Disclosed is the architecture that describes the protocol for
managing sequences, which includes a method to keep both ends of a
link in step when frame transmission is not being performed, called
"control synchronization".

      Serial I/O Architecture defines unique groups of special
transmission characters, called delimiters, to establish the extent
of a frame.  Serial I/O Architecture defines unique groups of a
special transmission character and a data character. When a unique
group is combined as a consecutive string, it provides a defined
sequence.

      Serial I/O Architecture unit of transmission is a frame.
Information is transferred in a frame as encoded fields in a serially
transmitted synchronous bit stream. Frame transmission provides a
method to keep both ends of a link in step.

Ordered-Set Reception

      Ordered-set reception is the process of receiving and
recognizing a group of transmission characters that satisfy a
prescribed ordered set. Ordered-set reception can start any time
after the receiver has achieved synchronization.  When
synchronization is achieved, the transmission-character boundaries of
the serial bits being received are established, which permit the
receiver to search for consecutive transmission characters that
constitute an ordered set.

      Ordered-set reception starts when a transmission character
received is the first transmission character of an ordered set.
Figs. 1 and 2 define the ordered sets of transmission characters.

      Ordered-set reception, when started, continues until one of the
following ordered-set-terminating conditions occur:
      1.   The next transmission character received does not
           sustain any ordered set and is not a valid first
           transmission character of another ordered set.
      2.   A code-violation error is detected.
      3.   A loss-of-signal condition is detected.
      4.   A loss-of-sync (loss of transmission-character
           synchronization) condition is detected.

      When ordered-set reception is ended before an ordered set has
been recognized, that which has been received is not considered to be
an ordered set and is discarded, and a link error is detected.
Whether the detected link error causes a link-error condition to be
recognized depends on the conditions present.  After ordered-set
reception is ended by one of the ordered-set-terminating conditions,
each subsequent transmission character received is checked to
determine if another ordered s...